Aerosol dispensing devices have been developed that include a dose indicating device to indicate the number of metered doses that have been dispensed from the device, or to indicate the number of doses remaining therein. For example, patients have certain conditions that can be treated with medicaments dispensed in an aerosol and administered to the patient by inhalation. In one format, the aerosol with medicaments are contained in a container, and dispensed in metered, or measured, dosages with an inhalation device, or actuator boot. In such an arrangement, it can be important for the patient to be able to ascertain the number of metered doses remaining in the container, either by an indication of the number remaining therein or by knowledge of the number already dispensed therefrom, such that the patient is not caught unaware with an empty container when in need of the medicament. Thus, it may be important for the inhalation device to provide an accurate indication of either the number of doses remaining in the container, or the number of doses already dispensed therefrom.
In some embodiments, for example metered dose inhalers configured with containers holding HFA propellant, the actuator nozzle or well may need to be cleaned periodically to ensure proper aerosol drug delivery and output. In conventional embodiments, the container is simply removed from the actuator and water is used to clear the actuator nozzle. However, when the dispensing device is configured with an indicator device, for example a device located in the actuator boot, there is potential for a different container to be associated with the actuator boot and indicator device, thereby leading to an inaccurate count of dosages dispensed from or remaining in that container.